The baking soda causes a reaction with the vinegar water mix, so be careful. As you can see from the video above, the liquid rose and spilled out of the jar. Give the mixture a minute to react and you'll start to see some of the noodles rise and fall. It's not on the video, but you can add another tablespoon of baking soda to continue the reaction and get more movement in the noodles.
Try it out yourself. It's a very cool experiment. Just have a towel or two handy. :-)